Internet search engines provide information about Internet accessible resources, e.g., Web pages, images, text documents, and multimedia content, that are responsive to user search queries. Internet search engines return a set of search results in response to a user submitted query. To provide better search results to users, search engines can modify queries to include normalized forms of search terms and variant forms of search terms. These normalized and variant forms are often determined according to dictionaries or observed co-occurrences of word forms in resources and search queries.